The Zynq webinar presentation slides

The ELMG Digital Power Electronics Control Course

Three days of focused unique training in digital control of power electronics!

Our Digital Power Electronics Control Course overs the essential knowledge and know-how for engineers to implement digital power electronic control!

Come to the Three Day Digital Control Course in Camarillo, California August 22-24, 2016. Register here.

How did the course came about?

Essentially the course came about because we were asked by one of our customer’s to provide one. The story is we were in the middle of a “fix up” job where the power supply had shown some control instability at its final release testing. The testing that showed the problem was passing a short circuit test of parallel connected power supplies. When the short circuit was removed the supplies came out of current limit, however they did not come out of the limit at exactly the same time. This created an oscillation where individual power supplies came out of current limit and then returned to current limit. It was possible for the oscillation to continue indefinitely. This was an unacceptable and embarrassing problem.

Six months of expertise in a three day course

During the six month project to rework the control code we spent lots of time teaching the team about the underlying issues that had been missed when the controller had been designed, coded and tested. And part way through the “fix-up” the R and D manager suggested we could put a course together covering all that the team needed to know.

And so the digital control course was born

The first course covered exactly what we had discovered during the fix up job. This included lots of digital expertise targeted for power electronics. The areas we covered were diverse from;

Numeric precision loss in filters

Improvement of modulation spectral performance

Stability

The effect of numeric precision on stability

Best filter forms

Direct digital control design

Linearising control loops

What is covered in our course?

The course was created at the request of a Power Electronics Research and Development manager. He asked that we make it specific his team’s needs. And this is why the course has the unique structure that it has. We have been through the pain and heartbreak of having digital control development go wrong and have seen clearly where the repeated problems lie; our course addresses those areas.

Digital PWM and VPO modulators

One of the big differences between digital power electronics control and conventional analog control is the timer precision in digital modulators. This difference can be corrected or made negligible and in some cases can be made an advantage. Spectral control in digital modulators is a focus area in the course as it is so effective.

Digital Precision in control blocks

It is possible to use a digital system and adjust the coefficients of the filters so that small inputs result in no output from the filter. Such scaling issues often lead to a loss of precision in the digital control system. The resulting slip-strike behavior can create limit cycle oscillations in the power converter output.

Direct Digital design of controllers

The “design then translation” approach of taking analog controllers to digital form can be avoided by using the direct digital design approach. This simple but powerful method of digital control loop design is covered in the course.

Converter non-linearity correction

Certain converter topologies are non-linear either in the control input to the output or the conversion ration. Dealing with the converter non-linearity to achieve high bandwidth is key to stable parallel connected converters.

Stability

The course covers the fundamentals of stability from a physical basis with a focus on measurements of power converter transfers. This along with a simple framework for managing margins and robustness is an integral part of the course.

Why we offer the course?

Understanding and implementing digital control of power electronics offers great advantages for configuration and flexibility. However, this is not without road blocks and issues that need to be designed around. This course provides the know how to get digital control working robustly and reliably.

How do I get on the course?

The course is next being run in Camarillo, California USA August 22-24. To register for the course, click and visit the information page here. Press the ‘Register’ button on the page and this will take you to the shopping cart for the course. Complete the purchase to register for the course.

Next course

The next course is being held August 22-24 in Camarillo, California, USA.

Hotels

HOTELS

There are several hotels a short distance from the Ridley Engineering Design Center. The prices below reflect their current prices for August 2016. The last hotel listed is a nice beachfront resort if you do not mind the 25-minute commute to the office. Regardless of your selection, we recommend arriving on Sunday evening and departing Wednesday evening or Thursday.

About the presenter

Dr. Hamish Laird

Dr. Hamish Laird is a well regarded digital power electronics control engineer, researcher, lecturer and teacher. Hamish is Chief Technology Officer at ELMG Digital Pwoer and holds a visiting academic position at the University of Canterbury in Christchurch, New Zealand.

During his career Dr Laird has worked on the control for;

High Voltage Direct Current Transmission

Reactive Power Compensators

AC and DC Motor Drives

DC to DC converters including LLC and phase shifted bridges

Medium and low voltage AC motor starters

Dr. Laird has worked for;

Alstom Grid (GEC Alsthom)

Eurotherm Drives

University of Canterbury

Aucom

Through ELMG Digital Power Dr. Laird has provided advice, services and products to;

ABB

Enphase

Comsys

Evashred

TNEI

Eaton

Dr Laird says

“In designing and presenting the course we aim to have engineers able to use digital control in power electronics to achieve robust and reliable results. See you in Camarillo”.

How to Register

P.S. Please note that the ELMG Digital Power course is being hosted at the Ridley Engineering Centre in Camarillo, California. Ridley Engineering are processing all course registrations viatheir webstore. Click here to register.

If you have just sat down at your desk with a coffee, then put that aside for a minute and grab your diary.

Review your schedule for Tuesday 12th July 2016 and consider this stellar opportunity: on that day ELMG Digital Power will be hosting a FREE webinar on Digital Power using Xilinx Zynq SoC.

That’s right, from the comfort of your own desk you can join ELMG Digital Power (Members of the Xilinx Alliance Program) for their Zynq Digital Power Webinar and expand your knowledge and expertise by discovering:

* What is important in digital power, including numeric precision and latency
* How to design a compensator in the digital domain
* Why you would use a FPGA for digital power and why the Zynq SoC in particular
* Key issues in digital controllers in programmable logic, such as the serial-parallel trade-off, fixed or floating point, choosing sample rates and what precision to use
* The building blocks for digital control and ELMG’s licensable IP cores
* IIR digital filter design (a case study) along with understanding the delta operator
* Using the ARM cores in the Zynq to your full advantage.

This webinar will be hosted and presented by Dr. Tim King, ELMG Digital Power’s Principal FPGA Engineer. Tim has considerable experience the design and implementation of varied digital control systems and IP for power electronics on FPGA platforms.

The webinar, which includes a short Q&A session, will be held on Tuesday 12th July and is available globally. Just choose a time that best suits you from these three options:

How can I look at my digital signals in my power controller?

One of the big issues when working on digital control of power electronics is being able to look at the digital signals inside your controller. In order to see what is going on inside the control the digital signals need to be brought out so you can look at them.

When a DAC isn’t good enough.

One way to do this is with a digital to analog converter (DAC) where the digital stream is sent out as an analogue signal. These DAC channels are really useful and should be on every digital power electronics controller. However processing power usually limits the logging or data streaming to a DAC to a low number of channels. Each channel requires a scope channel of its own to do measurement. Any measurement is limited in length to the scope’s memory and the scopes sample rate.

ELMG Digital Power ControlScope

Data Collection in the Controller and Detecting Events

There is also the issue that collecting enough data to allow event detection such as;

single sample errors

clipping

overflow

underflow or precision loss and

bursty instability due to precision loss

can be a very difficult large load on the control processor and memory if the data logging rate is very high or if the rate of the problem is very low.

Control Scope Integrated into Digital Power Controller

To solve this problem we put the data collection and logging into the controller but without loading the controller.

Using the Xlinx Zynq system on a chip (SoC) we use the flexibility of running Linux on one of the two ARM 9 cores to provide the high speed gigabit Ethernet connectivity.

Dlog Implementation

We also use the Linux for secure remote access if required.

Using ELMG Power Core IP blocks and know how we create firmware in the FPGA fabric of the Zynq. This connects to the Linux kernel and then the Linux user space. Data can be logged at full sample rates into SD cards or MMX memory and simultaneously out via the Gigabit Ethernet to the internet.

To be very clear no Linux code is included in the power electronics control function which is all implemented in the FPGA fabric on the Zynq.

Put a scope on the other end of the Ethernet

The video shows the ELMG ControlScope application connected to the ELMG Digital Power Zynq data collection system (named Dlog).

This system implements a fully functional oscilloscope that allows the internal operation of the digital control to be shown and logged.

With gigabit Ethernet logging rates of 25 M bytes per second are possible using Dlog.

This means that logging of your power converter performance and waveforms, scope function or debugging can be done over the internet.

Xilinx Zynq SoC is a great processor for digital power electronics control.

Dr. Tim King presents

The free webinar on digital power using Zynq will be hosted and presented by Dr. Tim King, ELMG Digital Power’s Principal FPGA Engineer. Tim has considerable experience the design and implementation of varied digital control systems and IP for power electronics on FPGA platforms.

This exciting opportunity is free and includes a short Q&A session with Dr. Tim King.

Dr Tim King

When and where

The webinar will be held on 12th July and is available globally in your time zone. Just choose a time that best suits you from these three options: